Williams' body was found in the bag in the bathtub of his apartment in London in August 2010. The unusual of his death — Williams, 31, a math prodigy who worked as a code breaker for the British spy service MI6, was discovered naked and showing no signs of a struggle — has transfixed Britain as details of Williams' transvestism and sexual fantasies have emerged.

Speaking at an official inquest into Williams' death in August 2010, the pathologist, Benjamin Swift, said the precise cause of death couldn't be pinpointed because the body was badly decomposed after having been in the bag for more than a week before it was found, The Guardian reported. But he said asphyxiation or poisoning were the "foremost contenders."

That has spawned any number of conspiracy theories that Williams may have been assassinated by foreign agents or terrorists. But MI6 said it believed his death had nothing to do with his work or that it had covered it up.